After nearly 30 years of pursuit, chemistry professor Lai-Sheng Wang finally witnessed something he thought would never materialize: a boron buckyball. Brown University researchers have discovered the first experimental evidence of an 80-atom boron buckyball—a soccer ball-shaped nanostructure that challenges decades of assumptions about what elements can build in the nanoscale world.
The discovery matters because carbon has dominated nanotechnology since the first buckyball was identified just over 40 years ago. That carbon version, Buckminsterfullerene, contained 60 atoms and sparked a revolution in materials science, leading to applications in medicine, energy technology, and beyond. If boron can achieve similar architectural feats, Wang's work suggests it might do so with even more interesting properties than its carbon cousin. Wang and his team—graduate students Hyun Wook Choi and Deniz Kahraman among them—published their findings in Chemical Science.
The path to this breakthrough was neither straightforward nor entirely expected. The researchers began by blasting a boron target with a high-powered laser, dislodging atoms that rapidly cooled into nanoclusters of various sizes. They then used photoelectron spectroscopy, an analytical technique Wang describes as producing a "fingerprint" for different molecular structures. The method works by zapping each cluster with a second laser to knock electrons free, then measuring how fast those electrons travel down what Wang calls his "electron racetrack." That speed reveals the cluster's electron binding energy spectrum—essentially a readout of how tightly the structure holds its electrons.
The photoelectron spectra of highly symmetrical structures produce distinct peaks. As Wang's team investigated progressively larger boron clusters, the spectra became increasingly featureless, suggesting unremarkable structures. Wang was skeptical about the 80-atom cluster. "My attitude at that time was that this was probably going to be a low-symmetry thing," he recalled. "I thought, we'll get this ugly spectrum, publish it, then it's the end of the story for this B80 cluster." When his student showed him the spectrum after a trip, Wang's skepticism evaporated instantly. The peaks stood out with unexpected clarity—hallmarks of a highly stable and symmetric structure.
Working with collaborators internationally, Wang's team determined that only one configuration could produce such a clean spectrum: the buckyball. The finding defies prediction. Density functional theory, the standard computational method for determining molecular properties, suggests the boron buckyball should be unstable. Yet after exhaustively searching possible 80-atom boron configurations, all experimental evidence pointed to one conclusion. "I really didn't think this structure was going to be stable and that we were going to disprove its existence," Wang said. "But when my student showed me the spectrum for the boron-80 cluster after I returned from a trip, I couldn't believe it."
This discovery represents a significant step in a decades-long quest. In 2013, Wang's team showed that 36-boron-atom clusters formed flat, one-atom-thick disks—work that inspired other labs to synthesize borophene, boron's graphene equivalent, two years later. In 2014, they demonstrated that a 40-atom boron cluster formed a hollow cage resembling a buckyball but lacking perfect spherical symmetry. Now, the 80-atom boron buckyball hints at a richer nanotech landscape where boron might finally claim a starring role alongside carbon.